One of the burgeoning areas of the development of modern microscopy is three-dimensional (3D) microscopy, which acquires three-dimensional image with every image plane sharply in focus. This is in contrast to conventional microscopy where the image of in-focus plane is superposed with blurred image of out-of-focus planes. Several developments of 3D microscopy have been reported. These techniques have been gaining popularity in the scientific and industrial communities. Typical applications include life sciences and semiconductor inspection.
An inverted microscope is a microscope with its light source and condenser on the top above the stage pointing down, and the objectives and turret are below the stage pointing up. Inverted microscopes are useful for observing living cells or organisms at the bottom of a large container (e.g. a tissue culture flask) under more natural conditions than on a glass slide, as is the case with a conventional microscope.
In confocal scanning microscopy (CSM), the out-of-focus signal is spatially filtered out by confocal aperturing of the object illumination and the detector points. The 3D image is constructed by pixel-by-pixel mechanical scanning of the entire object volume, which places a fundamental limit on the image acquisition speed.
A catadioptric system that uses a curved mirror to map a panoramic view onto a single sensor is able to obtain multi-perspective 3D images of an object, but has the limitation on sensor resolution. Furthermore, the resolution varies significantly with the viewing direction across the field of view (FOV).
Therefore, a heretofore unaddressed need exists in the art to address the aforementioned deficiencies and inadequacies.